1. Field of the Invention:
The present invention relates generally to a method of dispersing a liquid into another liquid and more particularly to a method of dispersing a refrigerant into a brine so as to produce solid crystals from the brine.
2. Prior Art:
Sea water desalination plants using the direct freezing method employ a crystallizer as the process vessel. This method and apparatus has not been found satisfactory notwithstanding various attempts to improve its structure and performance. The crystallizer contains sea water, the brine, with which a refrigerant, such as butane, is brought into direct contact for an increased degree of heat exchange. A conventional structure for such a crystallizer is illustrated in FIG. 1 of the accompanying drawings. A crystallizer 1 includes a pipe 2, fixedly disposed in a lower portion thereof and having a plurality of small holes 3 which open upwardly. The crystallizer 1 contains a brine 4 supplied from a supply pipe 5. A refrigerant is introduced through a conduit 6 into the pipe 2 and is ejected from the holes 3 into the brine 4. The ejected refrigerant is vaporized as it takes heat away from the brine 4, which is then refrigerated to form crystals of ice. The vaporized refrigerant moves upwardly and is discharged through a discharge pipe 7. The crystals of ice thus produced are discharged by a slurry discharge pipe 8.
To refrigerate the brine and produce crystals of ice effectively, it is necessary that the refrigerant be dispersed in as small droplets as possible into the brine to get a greater area of exposure to, or contact with, the brine for an increased degree of heat exchange therewith. In addition, the temperature and density of the brine in the crystallizer should be as uniform as possible.
In the prior crystallizer shown in FIG. 1, however, an attempt to make the holes 3 smaller, for smaller refrigerant droplets, would result in a greater pressure loss on the passage of the refrigerant through the holes 3. Furthermore, the refrigerant would have to be pressurized strongly for introduction into the pipe 2, and the small hole 3 would tend to get clogged.
The refrigerant discharged from the fixed holes 3 jets through the brine 4 and, when it has dispersed into droplets in the brine, the droplets tend to unite with each other. This is caused by the fact that the speed of the droplets is suddenly reduced by the resistance of the brine 4, and the droplets following in the same straight courses catch up with the first ejected droplets.
A mechanical agitator is usually added to the conventional crystallizer to get the brine 4 homogeneously stirred, but it requires a large power supply for effective stirring of the brine 4.